Drill-down packer

Claim 1

A ROTARY DRILL STRING PACKER, COMPRISING A TUBULAR BODY INSERTABLE IN A DRILL PIPE STRING TO FORM A PART THEREOF, AN ANNULAR FLEXIBLE SEALING MEANS MOUNTED ABOUT THE BODY FOR RADIAL EXPANSION IN RESPONSE TO AXIAL COMPRESSION THEREOF, PIPE-GRIPPING ANCHOR ELEMENTS MOUNTED ABOUT THE SEALING MEANS FOR RADIAL MOVEMENT THEREWITH, A CYLINDER SLIDABLY DISPOSED ABOUT SAID BODY IN SEALING ENGAGEMENT THEREWITH AND OPERABLY ENGAGED WITH ONE END OF THE SEALING MEANS FOR AXIALLY COMPRESSING THE SAME, THE INTERIOR OF SAID CYLINDER DEFINING A FLUID PRESSURE EXPANSIBLE CHAMBER, FLUID CONDUITS THROUGH THE WALL OF SAID BODY COMMUNICATING THE INTERIOR THEREOF WITH SAID CHAMBER, A SLEEVE VALVE MEMBER SLIDABLE IN THE BORE OF SAID BODY BETWEEN POSITIONS OPENING AND CLOSIONG SAID CONDUITS, RELEASABLE MEANS NORMALLY HOLDING SAID SLEEVE MEMBER IN THE CONDUIT-CLOSING POSITION, SAID PLUGGING MEANS INSERTABLE INTO THE BORE OF THE SLEEVE VALVE MEMBER TO CLOSE OFF THE BORE OF SAID PIPE STRING, SAID SLEEVE VALVE MEMBER BEING MOVABLE TO THE CONDUIT-OPENING POSITION BY FLUID PRESSURE FROM THE INTERIOR OF SAID BODY UPON CLOSING OF THE BORE OF THE SLEEVE VALVE MEMBER.